An overview of the virtues of an SRM Powermeter should first be prefaced by a quick summary of the virtues of training with power. There are a handful of excellent articles on the web that delve into this in great detail. Two of our favorites are the FAQ for training with power from the Wattage Forum at Topica.com. Another fantastic resource is Training and racing with a power meter: an introduction by Andrew R. Coggan, Ph.D. These articles confirm what many of us have experienced in our training: Monitoring heart rate is an unreliable means of gauging the true intensity of a given effort: (1) Circumstances other than exertion can affect your heart rate during a workout: altitude, temperature, state of hydration, illness, lack of sleep, terrain, and wind conditions. (2) Your heart rate doesn't instantaneously mirror your effort. The best example of this is a sprint or a short, steep climb. Your heart rate will be low at the early stage of an intense effort, but will be quite high even after the effort is completed (once the finish line is passed, the hill is crested, etc.) Measuring your efforts by analyzing power directly addresses the drawbacks of heart rate. As Dr. Coggan writes, "training with a power meter provides immediate and quantitative feedback on the intensity of effort. 300 Watts is 300 Watts, no matter how you feel, how hot, windy, or hilly it is, or what your heart rate is. It is the 'bottom line' measure of fitness." John Verheul -- accomplished cyclist, Senior Associate Coach with Cycle-Smart Solutions For Cycling, and good friend of Competitive Cyclist -- personally uses an SRM powermeter for his daily training and racing. Like many coaches, he prefers to design and prescribe programs based on power as the primary measure of intensity. "I see the use of powermeters as making the coaching relationship much more fruitful for both the coach and the client. In addition to the scientific advantages of power over heart rate or perceived exertion as a measure of intensity, the ability to look at every aspect of what a rider is doing (power, cadence, speed, and heart rate) at any moment is crucial to the complete analysis of a rider's performance. This leads to less educated guessing, more certainty in prescribing training programs and racing tactics, and more consistent performance gains as a result. The SRM powermeter with included software provides this information in a clear, reliable way that has enabled me to become a better, more effective coach. I spend less time figuring out what happened, and much more time making specific improvements in a client's training and racing approach." The SRM Powermeter is unquestionably the most sophisticated and most reliable means of measuring power. Inside the SRM crankset are strain gauges -- small pieces of metal whose electrical conductivity change as they are twisted or deformed. The changes in electrical conductivity caused by your pedaling forces are translated into watts. This wattage reading is a pure assessment of your effort. Along with wattage, the SRM has a heart rate monitor built in, and it also provides you with all of the typical functions of a cyclocomputer, such as current, average, and maximum speed, as well as actual (not virtual) cadence. You can customize the digital display of the computer, allowing you to choose 5 pieces of information to display on the screen at one time. The memory storage capacity of the SRM is amazing -- it can store up to 225 hours of ride time, so you Don't need to obsess about downloading your information after every ride. The software package that comes with the SRM is comprehensive enough even for pros with Tour de France aspirations. You can dissect your rides in exacting detail in a variety of graphical formats. Every ride is stored with a date and time, so it's easy to compare workouts to monitor the progress of your fitness. You can also enter comments with every training file as extra information about the training. An added plus is that SRM is excellent about continuously offering free upgrades and patches to their software. Downloading workouts to your computer is simple and quick through a serial port. You can convert the serial interface to a USB-based system with a bit of creativity. Consult your back issues of ProCycling and Cycle Sport magazine. In virtually every picture of European pros training, you'll see bikes outfitted with an SRM crankset. SRM cranks are so reasonably lightweight, in fact, that you're starting to see them appear on bikes during races as well. No investment is more valuable to a dedicated cyclist than the hours they spend training. The SRM Powermeter is unquestionably the most effective means of realizing maximum returns on this investment. Please note that all SRM systems are shipped for free via UPS Next Day Air, ensuring that you will receive your system the next business day after you order it.